Sympathetic Structures (Gray and White Rami Communicantes) & Innervation to the Skin

The video tutorial provides an in-depth look at the structure of the spinal cord, focusing on the anatomy of rootlets and the formation of spinal nerves. It explains the sensory and motor pathways, highlighting the roles of dorsal and ventral roots. The tutorial also covers the autonomic nervous system, particularly the sympathetic nervous system, detailing the function of white and gray rami communicants. It concludes with an explanation of sympathetic pathways and neuron communication, emphasizing the importance of understanding these processes for innervating peripheral areas like the skin.

What is the primary function of the dorsal root in the spinal cord?

• To regulate autonomic functions

• To transmit motor signals to muscles

• To carry sensory information to the spinal cord

• To connect the spinal cord to the brain

Which component of the spinal nerve is responsible for innervating the muscles of the back?

• Ventral ramus

• Dorsal ramus

• Dorsal root

• Ventral root

What is the role of the ventral ramus in the spinal nerve?

• To innervate the back muscles

• To form plexuses for limb innervation

• To carry sensory information from the skin

• To connect to the sympathetic chain ganglion

Which structure allows presynaptic neurons to enter the sympathetic chain ganglion?

• Gray ramus communicans

• White ramus communicans

• Dorsal root ganglion

• Ventral root

What is the function of the gray ramus communicans?

• To carry motor signals to muscles

• To return neurons from the sympathetic chain ganglion to the spinal nerve

• To transmit sensory information to the brain

• To connect the spinal nerve to the dorsal root

In the sympathetic nervous system, where does the postsynaptic neuron synapse?

• In the dorsal root ganglion

• In the spinal nerve

• In the sympathetic chain ganglion

• In the ventral root

How does the sympathetic nervous system innervate blood vessels in the skin?

• Through a loop involving the rami communicantes

• Via the dorsal ramus

• Directly through the ventral root

• By bypassing the spinal nerve